The present invention relates to liquid herbicidal emulsions containing as the active ingredient, the isopropylamine salt of N-phosphonomethylglycine, which is a water soluble herbicide in combination with a water-insoluble 2-haloacetanilide herbicide, preferably 2-chloro-N-methoxymethyl-2',6'-diethylacetanilide. The herbicidal emulsions described herein are advantageously employed to replace mechanical tillage in the preparation of a seedbed in no-tillage farming.
No-tillage refers to a wide variety of crop production systems using reduced or limited amounts of tillage. Various estimates indicates that by the year 2010 over 90% of the cropland in the United States will be planted using no-till methods. No-till farming is advantageous in that it saves water because there is less run-off, less direct evaporation losses and thus more water available for crop growth and higher yields. No-till reduces the number of field operations along with labor and machinery requirements with corresponding savings of fuel. In areas where double-cropping is practical, no-till enables the farmer to plant a second crop as the first crop is harvested. No-till also offers the opportunity to farm more extensively on, for example, sloping land where erosion is a problem if the crop is planted using conventional plowing. However, successful practice of no-till farming requires that the farmer rely almost completely on herbicides for weed control. The use of herbicides replaces mechanical tillage in the preparation of the seed bed. No-tillage usually requires a combination of a contact herbicide for quick burn-down of existing vegetation and use of one or more residual herbicides to provide season-long weed control. Because in the practice of no-tillage farming, the farmer almost totally relies upon agricultural chemicals for control of unwanted vegetation, proper preparation and application of the herbicides is critical. Generally speaking, in the practice of no-tillage farming, the herbicide is applied by spraying; thus, usage of correct spray nozzles, right sprayer speed, right amount of water or liquid nitrogen carrier, and, most importantly, proper mixing of the herbicides is highly important.
It is known in the art that a formulated composition containing, as the active ingredient, the isopropylamine salt of N-phosphonomethyl glycine which is sold under the tradename Roundup.RTM., may be tank-mixed with formulated 2-chloro-N-methoxymethyl-2',6'-diethylacetanilide (commonly known as alachlor and commercially available under the tradename Lasso.RTM.).
The isopropylamine salt of N-phosphonomethyl glycine (also known as the IPA salt of glyphosate) is a superior post-emergent herbicide effective against a broad spectrum of weeds. 2-Haloacetanilide herbicides, on the other hand, are preferentially employed as preemergent herbicides and are especially effective in the control of the grass weeds. Tank-mixtures of commercially available formulations of these two types of herbicides, especially Roundup.RTM. herbicide tank-mixed with Lasso.RTM. herbicide, have proven very useful in no-till or minimum till farming.
In actual use, tank-mixtures suffer from the disadvantage that such mixtures require that the farmer must purchase and store two separate herbicides until actual preparation of the tank-mixture, which is an inconvenience. The farmer is also required to measure out varying amounts of the two different herbicides allowing for the possibility of mixing errors. Accordingly, a pre-packaged mixture containing both types of herbicides in one container is highly desirable since the farmer only has to purchase and store the pre-packaged mixture containing both of the active ingredients and the possibility of mixing errors is eliminated.
The herbicidal emulsions of the present invention provide flowable, herbicidal emulsion compositions in which a water-soluble herbicide, i.e., the isopropylamine salt of glyphosphate is combined with a water-insoluble 2-haloacetanilide herbicides, e.g., 2-chloro-N-methoxymethyl-2',6'-diethylacetanilide as a pre-packaged, one-container mixture which is conveniently stored, is storage-stable and easily dispersed in water and which can contain a high concentration of the herbicide active ingredients, e.g., up to and including about eight pounds herbicide per gallon of formulation.